Mobile phones can now double as stun guns or pepper spray dispensers in a controversial new safety trend, reports CBS New York.

The $140 Yellow Jacket smartphone case may be able to ward off an attacker, device creators Simon Simone and Seth Froom tell the station. With the press of a button, two electrodes at the top of the code will deliver 650,000 volts of electricity.

While the strength of the Yellow Jacket is less than that of a stun gun -a stun gun delivers several million volts - it was developed "to be able to take down a fully aggressive adult male," Froom told the station.

Stun guns, including the Yellow Jacket, are not legal in states including New York and New Jersey. Another device, the Spraytecht, is, however - the $40 smartphone case includes a removable pepper spray cartridge.

Some critics argue that the devices may offer a false sense of security, however.

"Just because you have something doesn't mean you have trained yourself in how to use it," James Sherman, who specializes in the Israeli self defense technique of Krav Maga, told the station. "They're definitely beneficial, but you have to learn what to do with it."